Diketahui sistem persamaan linier tiga variabel berikut.

3x – 2y = – 10
4x + 5z = 21
4y – 3z = – 43

3x – 2y = – 10
– 2y = – 10 – 3x
– y = – 5 – 3/2x
y = 5 + 3/2x

4y – 3z = – 43
4(5 + 3/2x) – 3z = – 43
20 + 6x – 3z = – 43
6x – 3z = – 43 – 20
6x – 3z = – 63
2x – z = – 21

2x – z = – 21|× 2
4x + 5z = 21|× 1

4x – 2z = – 42
4x + 5z = 21
__________ —
– 7z = – 63
z = 9

2x – z = – 21
2x – 9 = – 21
2x = – 21 + 9
2x = – 12
x = – 6

y = 5 + 3/2x
y = 5 – 9
y = – 4

– Nilai 2x – y – z
2x – y – z
= – 12 + 4 – 9
= – 8 – 9
= – 16

Maaf Kalau Salah

3x-2y=-10
4x+5z =21
4y-3z=-43

3x=-10+2y
x= -10/3 + 2y/3
masukkan nilai x ke persamaan kedua
4(-10/3 + 2y/3) +5z=21
-40/3 + 8y/3 + 5z = 21 (kali dengan 3 semuanya)
-40 + 8y +15z =63
8y+15z=103
ke pers ke tiga
8y +15z=103
4y-3z=-43(kali dengan 2)
jadinya::::
8y +15z=103
8y-6z=-86
——————– –
21z = 189
z= 9

4x+5z=21
4x+45=21
4x=24
x=6

3x-2y=-10
18-2y=-10
-2y=-28
y=14

nilai 2x-y-z adalah
12-9-14 = -11

Maaf kalo salah